With the simplest of modifications, a normal ink-jet printer becomes a high-tech 3-D printer, able to build replacement skin for those desperately in need of grafts. The latest breakthrough saw a plastic "ear" being printed out over just a half-hour...and it's only a matter of time before we can do that with skin as well.

A couple research teams have been working on this idea, with a Wake Forest team attracting substantialattention. But this new breakthrough is the work of Cornell researchers, who have devised a simple 3D printer that can combine donor cells and other key materials to create replacement cartilage. Lead researcher Hod Lipson explains what's going on here:

"It spits out plastic to gradually build an object layer by layer... after a couple of hours you end up with a real physical object that you can hold in your hand. Just imagine — if you could take cells from a donor, culture them, put them into an ink and recreate an implant that is alive and made of the original cells from the donor — how useful that would be in terms of avoiding rejection. That is where we are going. Let's see how far we can go. [But] there are very severe limitations. We are right now limited to cells... that can handle being printed."

So far, the type of cells that has worked best is cartilage, which is strong enough to withstand the rigors of the printing process. But the basic technology is remarkably simple - it's just a regular ink-jet printer with an "elevator" added that allows it to print in three dimensions, plus its ink cartridges is replaced with cell cultures.